From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id D0A61C4167B for ; Sat, 25 Nov 2023 15:37:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:In-Reply-To:References: Message-ID:Date:Subject:CC:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=8izuF4HmzUlVYEQuqnIELNB/6TBD5jEm0WMQLM3bM6Y=; b=OlUmKuDDEU6icK FscmzmGvywcZ/pDfO/lGU7R24kC7pkSLAlaIjI4qqj4arkUhThrsomPoNDFhXHGqS/2qF/FFjJsF6 4yNQ87l1dZXWB3dBsdLW7uZAoTEEAJxZgs9nRKTFcBPtgTzIXU88Rem1e429ZGPtJxpCOk07ZXvWa lfbUhmx+ajgMWxwfokFowCCOOzRKIBk8rBWcLK2Wb5opchX5SQc3QG1IaJ8mKNzms2ZzM8Tix1jV7 dVTmRm4CHdMIWhK+rdFO4cpxzq+oeaETnGnjO3YV7nb0PMQ4v+L5Shd5RfGDmDTwXbdf6jMyfCuqN 2zF7tyOLGjQeFjOOSkqw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1r6uir-009QKH-0S; Sat, 25 Nov 2023 15:37:33 +0000 Received: from eu-smtp-delivery-151.mimecast.com ([185.58.86.151]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1r6uio-009QIz-0j for linux-riscv@lists.infradead.org; Sat, 25 Nov 2023 15:37:31 +0000 Received: from AcuMS.aculab.com (156.67.243.121 [156.67.243.121]) by relay.mimecast.com with ESMTP with both STARTTLS and AUTH (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384) id uk-mta-323-ACZXAgEhNOSnwO7T2ON0-A-1; Sat, 25 Nov 2023 15:37:22 +0000 X-MC-Unique: ACZXAgEhNOSnwO7T2ON0-A-1 Received: from AcuMS.Aculab.com (10.202.163.4) by AcuMS.aculab.com (10.202.163.4) with Microsoft SMTP Server (TLS) id 15.0.1497.48; Sat, 25 Nov 2023 15:37:39 +0000 Received: from AcuMS.Aculab.com ([::1]) by AcuMS.aculab.com ([::1]) with mapi id 15.00.1497.048; Sat, 25 Nov 2023 15:37:39 +0000 From: David Laight To: =?utf-8?B?J0Nsw6ltZW50IEzDqWdlcic=?= , Paul Walmsley , Palmer Dabbelt , Albert Ou , "linux-riscv@lists.infradead.org" , "linux-kernel@vger.kernel.org" CC: Christoph Hellwig , Ben Dooks , kernel test robot Subject: RE: [PATCH v2] riscv: fix incorrect use of __user pointer Thread-Topic: [PATCH v2] riscv: fix incorrect use of __user pointer Thread-Index: AQHaHsrcAiRrTVkzkEi8HCpEAmrYerCLK9Cg Date: Sat, 25 Nov 2023 15:37:39 +0000 Message-ID: References: <20231124113803.165431-1-cleger@rivosinc.com> In-Reply-To: <20231124113803.165431-1-cleger@rivosinc.com> Accept-Language: en-GB, en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.202.205.107] MIME-Version: 1.0 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: aculab.com Content-Language: en-US X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20231125_073730_546459_0BA945C6 X-CRM114-Status: UNSURE ( 8.12 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org ... > @@ -491,7 +486,7 @@ int handle_misaligned_load(struct pt_regs *regs) > > val.data_u64 = 0; > for (i = 0; i < len; i++) { > - if (load_u8(regs, (void *)(addr + i), &val.data_bytes[i])) > + if (load_u8(regs, addr + i, &val.data_bytes[i])) > return -1; > } I'd really have thought that you'd want to pull the kernel/user check way outside the loop? In any case, for a misaligned read why not just read (addr & ~7)[0] and (if needed) (addr & ~7)[1] and then ahift and or together? clang will do it for misaligned structure members with known misalignment, but it is almost certainly also better for reads with unknown misalignment. David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales) _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv